And yet it moves: Recovery of volitional control after spinal cord injury.

Preclinical and clinical neurophysiological and neurorehabilitation research has generated rather surprising levels of recovery of volitional sensory-motor function in persons with chronic motor paralysis following a spinal cord injury. The key factor in this recovery is largely activity-dependent plasticity of spinal and supraspinal networks. This key factor can be triggered by neuromodulation of these networks with electrical and pharmacological interventions. This review addresses some of the systems-level physiological mechanisms that might explain the effects of electrical modulation and how repetitive training facilitates the recovery of volitional motor control. In particular, we substantiate the hypotheses that: (1) in the majority of spinal lesions, a critical number and type of neurons in the region of the injury survive, but cannot conduct action potentials, and thus are electrically non-responsive; (2) these neuronal networks within the lesioned area can be neuromodulated to a transformed state of electrical competency; (3) these two factors enable the potential for extensive activity-dependent reorganization of neuronal networks in the spinal cord and brain, and (4) propriospinal networks play a critical role in driving this activity-dependent reorganization after injury. Real-time proprioceptive input to spinal networks provides the template for reorganization of spinal networks that play a leading role in the level of coordination of motor pools required to perform a given functional task. Repetitive exposure of multi-segmental sensory-motor networks to the dynamics of task-specific sensory input as occurs with repetitive training can functionally reshape spinal and supraspinal connectivity thus re-enabling one to perform complex motor tasks, even years post injury.

Adolescents' Communication with Parents, Other Adult Family Members and Teachers on Sexuality: Effects of School-Based Interventions in South Africa and Tanzania.

Cluster-randomized controlled trials were carried out to examine effects on sexual practices of school-based interventions among adolescents in three sites in sub-Saharan Africa. In this publication, effects on communication about sexuality with significant adults (including parents) and such communication as a mediator of other outcomes were examined. Belonging to the intervention group was significantly associated with fewer reported sexual debuts in Dar es Salaam only (OR 0.648). Effects on communication with adults about sexuality issues were stronger for Dar es Salaam than for the other sites. In Dar, increase in communication with adults proved to partially mediate associations between intervention and a number of social cognition outcomes. The hypothesized mediational effect of communication on sexual debut was not confirmed. Promoting intergenerational communication on sexuality issues is associated with several positive outcomes and therefore important. Future research should search for mediating factors influencing behavior beyond those examined in the present study.

An Overview of HIV Prevention Interventions for People Who Inject Drugs in Tanzania.

In the past decade, Tanzania has seen a rapid rise in the number of people who inject drugs (PWID), specifically heroin. While the overall HIV prevalence in Tanzania has declined recently to 5.6%, in 2009, the HIV prevalence among PWID remains alarmingly high at 35%. In this paper, we describe how the Tanzania AIDS Prevention Program (TAPP), Médecins du Monde France (MdM-F), and other organisations have been at the forefront of addressing this public health issue in Africa, implementing a wide array of harm reduction interventions including medication-assisted treatment (MAT), needle and syringe programs (NSP), and "sober houses" for residential treatment in the capital, Dar es Salaam, and in Zanzibar. Looking toward the future, we discuss the need to (1) extend existing services and programs to reach more PWID and others at risk for HIV, (2) develop additional programs to strengthen existing programs, and (3) expand activities to include structural interventions to address vulnerabilities that increase HIV risk for all Tanzanians.

Flashblood: blood sharing among female injecting drug users in Tanzania.

AIMS: This study examined the association between the blood-sharing practice of 'flashblood' use and demographic factors, human immunodeficiency virus (HIV) status and variables associated with risky sex and drug behaviors among female injecting drug users. Flashblood is a syringe-full of blood passed from someone who has just injected heroin to someone else who injects it in lieu of heroin. DESIGN: A cross-sectional study. SETTING: Dar es Salaam, Tanzania. PARTICIPANTS: One hundred and sixty-nine female injecting drug users (IDUs) were recruited using purposive sampling for hard-to-reach populations. MEASUREMENTS: The association between flashblood use, demographic and personal characteristics and risky sex and drug use variables was analyzed by t-test and chi(2) test. The association between flashblood use and residential neighborhood was mapped. FINDINGS: Flashblood users were more likely to: be married (P = 0.05), have lived in the current housing situation for a shorter time (P < 0.000), have been forced as a child to have sex by a family member (P = 0.007), inject heroin more in the last 30 days (P = 0.005), smoke marijuana at an earlier age (P = 0.04), use contaminated rinse-water (P < 0.03), pool money for drugs (P < 0.03) and share drugs (P = 0.000). Non-flashblood users were more likely to live with their parents (P = 0.003). Neighborhood flashblood use was highest near downtown and in the next two adjoining suburbs and lowest in the most distant suburbs. CONCLUSIONS: These data indicate that more vulnerable women who are heavy users and living in shorter-term housing are injecting flashblood. The practice of flashblood appears to be spreading from the inner city to the suburbs.

HIV seroprevalence in a sample of Tanzanian intravenous drug users.

Injection drug use has recently emerged in sub-Saharan Africa. The purpose of this study was to assess the factors associated with increased risk of testing HIV-positive in a sample of injection drug users (IDUs) in Dar es Salaam, Tanzania. Participants were recruited by a trained outreach worker or were referred by IDUs who had completed the study. Blood specimens and self-reported socioeconomic and behavioral data were collected from 315 male and 219 female IDUs. Data were analyzed using univariate odds ratios and multivariate logistic regression modeling. Forty-two percent of the sample tested HIV-positive. Several socioeconomic, injection, and sexual factors were found to be associated with increased odds of testing HIV-positive. Multivariate analysis showed that having had sex more than 81 times in past 30 days, earning less than 100,000 shillings (US$76) in the past month, residency in Dar es Salaam for less than 5 years, and injecting for 3 years were independently associated with the greatest risk of infection. The rate of HIV infection in this sample of IDUs was found to be very high, suggesting that injection drug use may be a factor in the continuing epidemic in sub-Saharan Africa. The factors associated with increased risk of HIV infection suggest further research is needed on the needle use and sexual networks of IDUs.

Parents' and teachers' communication about HIV and sex in relation to the timing of sexual initiation among young adolescents in Tanzania.

AIMS: Early sexual debut is associated with increased HIV risk among young adolescents in sub-Saharan Africa. Our study examines parents' and teachers' communication about sexual matters in relation to the timing of sexual initiation among students aged 12-14 years old in Dar es Salaam, Tanzania. METHODS: Virgin primary school students were followed prospectively for 6 months to assess sexual initiation. Socio-demographic, psychosocial, and behavioural factors were assessed with a structured questionnaire. Univariate and multivariate logistic regression analyses were performed. RESULTS: Of 2477 adolescents, 26.9% of students reported communicating about HIV and sex with parents and 35.6% communicated with teachers. Communication with teachers about HIV and sex was associated with delayed sexual initiation among adolescents after adjusting for potential confounding factors (OR=0.59, 95%CI=0.40-0.89, p=0.01). However, parental communication was not associated with the timing of sexual initiation. The perception that most peers are sexually active was a significant predictor of early sexual debut (test for linear trend, p=0.002). Students who do not live with a biological mother were marginally more likely to initiate sex compared to those who live with a biological mother (OR=1.39, 95%CI=0.97-1.99, p=0.08). CONCLUSIONS: Teachers can play an effective role in discussing HIV and sex with young adolescents. Our study highlights the necessity of responsible adults discussing sexual matters with young adolescents in sub-Saharan Africa. More research is required to better understand the role of parental communication about sexual matters and strategies for improving the quality of parental communication.

HIV risk behaviors in sub-Saharan Africa and Northern Thailand: baseline behavioral data from Project Accept.

BACKGROUND: Of 2.5 million new HIV infections worldwide in 2007, most occurred in sub-Saharan Africa and southeast Asia. We present the baseline data on HIV risk behaviors and HIV testing in sub-Saharan Africa and northern Thailand from Project Accept, a community-randomized controlled trial of community mobilization, mobile voluntary counseling and testing (VCT), and posttest support services. METHODS: A random household probability sample of individuals aged 18-32 years yielded a sample of 14,657, with response rates ranging from 84%-94% across the 5 sites (Thailand, Zimbabwe, Tanzania, and 2 in South Africa). Individuals completed an interviewer-administered survey on demographic characteristics, HIV risk behaviors, and history of VCT. RESULTS: In multivariate analysis, females, married individuals, less educated with 1 sexual partner in the past 6 months were more likely to have had unprotected intercourse in the previous 6 months. Rates of lifetime HIV testing ranged from 5.4% among males in Zimbabwe to 52.6% among females in Soweto. CONCLUSIONS: Significant risk of HIV acquisition in Project Accept communities exists despite 2 decades of prevention efforts. Low levels of recent HIV testing suggest that increasing awareness of HIV status through accessible VCT services may reduce HIV transmission.

Differences in HIV risk behaviors by gender in a sample of Tanzanian injection drug users.

This study investigated differences in drug use and sexual behaviors among from 237 male and 123 female heroin users in Dar es Salaam, Tanzania. Multivariate models of risk of needle sharing were estimated using multivariate logistic regression. Men were significantly older, more likely to inject only white heroin, share needles, and give or lend used needles to other injectors. Women were more likely to be living on the streets, have injected brown heroin, have had sex, have had a higher number of sex partners, and have used a condom with the most recent sex partner. Being male and earning less than US $46 in the past month were significant predictors of increased risk of needle sharing. Despite differences in sociodemographic, drug use, and sexual behaviors by gender, both male and female injectors in Dar es Salaam exhibit elevated risk of HIV infection associated with drug use.

Sustained silver-releasing dressing in the treatment of diabetic foot ulcers.

This study investigated the clinical performance and safety of a sustained silver-releasing foam dressing, Contreet Foam, in the treatment of diabetic foot ulcers. Twenty-seven patients with diabetic foot ulcers of grade I or II (Wagner's classification) were followed for six weeks: one week run-in using Biatain dressings, four weeks' treatment with Contreet dressings. Four ulcers healed during the four-week treatment with Contreet 56% in average. Contreet Foam showed good exudate management properties and was considered easy to use. Only two infections occurred showed that all six of the non-study ulcers developed an infection during the study. All ulcers (study ulcers as well as non-study ulcers) were treated according to good practice of diabetic wound care. There were no directions for the treatment of secondary wounds. No device-related adverse events were observed. This study demonstrated that Contreet Foam is safe and easy to use and effectively supports healing and good wound progress of diabetic foot ulcers.

High rates and positive outcomes of HIV-serostatus disclosure to sexual partners: reasons for cautious optimism from a voluntary counseling and testing clinic in Dar es Salaam, Tanzania.

The rates, barriers, and outcomes of HIV serostatus disclosure to sexual partners are described for 245 female voluntary counseling and testing (VCT) clients in Dar es Salaam, Tanzania. VCT clients were surveyed 3 months after HIV testing to describe their HIV-serostatus disclosure experiences. Sixty-four percent of HIV-positive women and 79.5% of HIV-negative women (p = 0.028) reported that they had shared HIV test results with their partners. Among women who did not disclose, 52% reported the reason as fear of their partner's reaction. Both 81.9% of HIV-negative women and 48.9% of HIV-positive women reported that their partner reacted supportively to disclosure (p < 0.001). Less than 5% of women reported any negative reactions following disclosure. VCT should continue to be widely promoted. However, intervention approaches such as development of screening tools and new counseling approaches are important to ensure the safety of women who want to safely disclose HIV serostatus to their sexual partners.

HIV-positive women report more lifetime partner violence: findings from a voluntary counseling and testing clinic in Dar es Salaam, Tanzania.

OBJECTIVES: Experiences of partner violence were compared between HIV-positive and HIV-negative women. METHODS: Of 340 women enrolled, 245 (72%) were followed and interviewed 3 months after HIV testing to estimate the prevalence and identify the correlates of violence. RESULTS: The odds of reporting at least 1 violent event was significantly higher among HIV-positive women than among HIV-negative women (physical violence odds ratio [OR] = 2.63; 95% confidence interval [CI] = 1.23, 5.63; sexual violence OR = 2.39; 95% CI = 1.21, 4.73). Odds of reporting partner violence was 10 times higher among younger (< 30 years) HIV-positive women than among younger HIV-negative women (OR = 9.99; 95% CI = 2.67, 37.37). CONCLUSIONS: Violence is a risk factor for HIV infection that must be addressed through multilevel prevention approaches.

Light microscopical study of dendrites and perikarya of interneurones mediating la reciprocal inhibition of cat lumbar alpha-motoneurones.

Interneurones which mediate disynaptic inhibition from la muscle spindle afferents of the quadriceps nerve to lumbar alpha-motoneurones were stained with intracellular injection of horseradish peroxidase. Seven best stained and most satisfactorily preserved cells were selected for analysis, and the light microscopic morphology of their cell bodies and dendrites were quantitatively investigated in parasagittal sections. The perikarya were located dorsal or dorso-medial to the motoneurones; they had mean diameters of 51 x 27 microns and a mean volume of 35,820 microns 3. The cells had 3 to 7 dendrites, which were arranged asymmetrically around the parent somata. The dendrites extended mainly in the dorso-ventral direction, in which the mean tip to tip distance for each cell was 1742 microns. The dendrites had few spines and they branched almost only in bifurcations. On the average, each process divided 3.5 times and in each cell they gave rise to 14.9 branching points as well as a total combined length of more than 7000 microns. Primary dendrites had a mean length of 193 microns which was generally shorter than the lengths of the branches of higher order. A more detailed analysis of two cells revealed the mean width of primary dendrites to be 5.6 microns while that of the 5th order processes was 1.5 microns. The mean tapering of individual dendritic branches per unit length was 17%, being somewhat more pronounced for the distally located segments, while at branching points the sum of daughter processes approximately equalled the diameter of the parent process.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipoprotein lipase activity and intramuscular triglyceride stores after long-term high-fat and high-carbohydrate diets in physically trained men.

Men with regular physical training habits voluntarily increased their dietary fat intake from 43 to 54% of energy (E%) for four weeks. This was followed by a low-fat (29 E%), high-carbohydrate diet for another four weeks. During the high-fat diet period, the muscle lipoprotein lipase activity (LPLA) increased from 59 +/- 8 to 106 +/- 12 mU/g (mean +/- SE) (P less than 0.05). After the high-carbohydrate diet, LPLA was 57 +/- 16 mU/g, and unchanged relative to the pre-trial value. The triglyceride content in m. vastus lateralis increased from 30 +/- 4 to 47 +/- 9 mmol/kg d.w. (P less than 0.05; mean +/- SE) following the high-fat diet and to 41 +/- 8 following the high-carbohydrate diet. Neither of the diets affected the serum triglyceride and insulin concentrations, nor glucose, glycerol, beta-hydroxybutyrate, citrate and lactate levels in the blood. Nor did they alter enzyme activities in muscle used as markers for the oxidative (citrate synthase, beta-hydroxy-acyl CoA dehydrogenase) and glycolytic (glyceraldehyde phosphate dehydrogenase, lactate dehydrogenase) capacity. It is concluded that one month's adaptation to a high-fat diet results in increased muscle-LPL activity indicating a higher capacity for uptake of fatty acids from circulating serum triglycerides into the muscle cell in association with a greater capacity for triglyceride storage in the muscle. Under these conditions serum triglycerides were not decreased despite the increased muscle LPLA, and serum insulin variations could not explain the change in muscle LPLA.(ABSTRACT TRUNCATED AT 250 WORDS)

Minor dietary effects of HDL in physically active men.

In a preceding prospective study an increased high-density lipoprotein (HDL)-cholesterol and apolipoprotein (apo) A-I concentration occurred in healthy, non-obese, initially sedentary men, aged 30--44 years, after 3 months of physical training. Dietary history data revealed an increase in the absolute amount of fat-intake. In the present study we investigated whether a changed fat intake would influence the levels of lipoproteins, especially the HDL fraction, in twenty-three regularly conditioning men, aged 30--44 years, with a maximal aerobic capacity of 53.4 ml/kg x min--1 +/- 0.8, mean +/- SE. Ten subjects participated in an experimental group and thirteen in a control group. The experimental group studied before, after 4 weeks on a fat-rich diet (fifty-four energy-% fat, twenty-nine energy-% carbohydrate) and after 4 weeks on a fat-poor diet (twenty-nine energy-% fat, fifty-three energy-% carbohydrate). The data reveal that these large dietary changes did not influence HDL-cholesterol concentrations (1.71 +/- 0.10, 1.69 +/- 0.12, 1.59 +/- 0.13 mmol/l, mean +/- SE, during ordinary, fat-rich and fat-poor diet, respectively) and only influenced apo A-I levels to a minor degree after the fat-poor diet (134 +/- 6.1, 134 +/- 7.1 and 123 +/- 4.7 arbitrary units, mean values +/- SE) during ordinary, fat-rich and fat-poor diet, respectively). No changes were observed in the controls before and after 8 weeks. During the study training habits and body weight were constant. These findings show that large variations in the intake of dietary neutral fat only to a minor extent influence the level of HDL-cholesterol and apo A-I in physically active subjects.

Non-autonomic component in bradycardia of endurance trained men at rest and during exercise.

Autonomic nervous alterations have generally been held responsible for the bradycardia of the endurance athlete. In order to determine whether there is also a non-autonomic component in the bradycardia of long-term training, we compared the intrinsic heart rate (HR) of highly trained bicyclists (heart volume: 995 +/- 155 ml) with that of untrained men (heart volume: 805 +/- 195 ml) at rest and during bicycle ergometer exercise at 50, 75 and 100% of maximal oxygen uptake (VO2 max.) Intrinsic HR was achieved by combined vagal and beta-adrenergic blockade with atropine and propranolol or metoprolol (cardioselective) injected intravenously. Intrinsic HR was significantly lower in trained (T) than in untrained (UT) at rest and at all levels of exercise. The chronotropic reserve from resting HR to maximal HR was identical in the two groups. Nearly identical intrinsic HRs were achieved with atropine and either beta-adrenergic antagonist. HR differences between T and UT were very similar in magnitude--approximately 13 beats/min--at rest and during exercise at a given percentage of VO2 max, with and without autonomic blockade. Evidence is thus provided for a non-autonomic component in the bradycardia of well-trained men which may be responsible for a parallel downward shift in the relationship between HR and percentage of VO2 max. The lower intrinsic HR in well-trained men might be explained by, i.a. the cardiac enlargement.